1. Field of the Invention
This invention relates to magnetic bubble domain devices in general and to a switching ciruit in particular. The particular switch is readily suited for one-level implementation.
2. Prior Art
Magnetic bubble domain chips are now receiving a substantial amount of interest as a new information handling technology. Many chips and device components have been developed in the past. Among the components which are necessary to permit the fabrication of a chip is a switching device which will transfer information from one path to another. Switches of this type are known in the art. For example, replicate-annihilate switches are described in "Evolution of Bubble Circuits Processed by a Single Mask Level" by A. H. Bobeck et al, in IEEE Trans. on MAG., Vol. MAG-9, No. 3, Sept. 1973, pp. 474-480. This paper describes a basic replicator component which consists of two adjacent propagate channels and a conductor loop. In this component, the chevrons of the adjacent channels have the apices pointing in opposite directions, namely, toward each other. During the application of a current signal to the conductor loop, the chevron groups in the adjacent propagaton channels have like magnetic poles in alignment. Thus, when bubbles are replicated, the bubbles react to the poles of the chevrons and move in opposite directions along the propagation paths. This limitation is important in some device operations.
Reference is also made to a paper entitled "Progress in All-Permalloy Bubble Control Functions" by T. J. Nelson, AIP Conference Proceedings, No. 18, Part 1, pp. 95-99 (1974). In this paper there is described the design and operation of an all-permalloy transfer gate using adjacent propagation paths (major-minor loops) composed of chevron elements. In this transfer gate, the spices of the chevron groups in the adjacent paths are, again, pointed toward each other. However, in the transfer gate described in this publication, a single current conductor intersects the apices of the adjacent chevron element groups. Again, this transfer gate has the disadvantage that bubbles propagate in different directions in the adjacent propagation paths. It also has the disadvantage that it cannot be easily incorporated into a major/minor loop chip design because a return current path must be provided.